Solar Heat Transmission through Windows
Sun Radiation through Windows
Heat gain from sun radiation through windows can be controlled with shades or blinds.
| Type of Shading | Transmitted Solar Energy (%) | Reflected Solar Energy (%) | Absorbed Solar Energy (%) |
|---|---|---|---|
| Single or double glass without shading | 75 - 80 | 10 - 20 | 10 - 20 |
| Vertical Blinds | 5 | 40 - 60 | 35 - 55 |
| Venetian Blinds | 0 | 23 | 77 |
| Roller Shades | < 25 | 15 - 80 | 20 - 65 |
Effect of Shading compared with unshaded Window
| Types of Shading | Fraction of Gain through Unshaded Window |
|---|---|
| Unshaded Window | 1.00 |
| Inside roller shade - half-drawn | 0.80 |
| Inside roller shade - fully-drawn | 0.62 |
| Inside venetian blind | 0.65 |
| Canvas awning | 0.30 |
| Outside shading screen - solar altitude 20o | 0.38 |
| Outside shading screen - solar altitude 30o | 0.25 |
| Outside shading screen - solar altitude 40o | 0.18 |
Related Topics
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Air Conditioning systems - heating, cooling and dehumidification of indoor air for thermal comfort.
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